[asterisk-users] How accurate is show translation?

[Gordon Henderson]

On Sat, 23 Dec 2006, Leo Ann Boon wrote:

> At this point, I don't feel that 'show translation' is a useful indicator of 
> actual transcoding performance. It's OK for relative comparisons but utterly 
> useless if you need the figures for sizing purposes.

Just to give you another (relative)  comparison... This is from a VIA 
processor running at 533MHz, (64KB Cache) asterisk compiled as i586 as 
it's missing some of the nicer MMX instructions:

          g723   gsm  ulaw  alaw  g726 adpcm  slin lpc10  g729 speex  ilbc
    g723     -     -     -     -     -     -     -     -     -     -     -
     gsm     -     -    10    10    32    12     9    43     -     -   174
    ulaw     -    18     -     1    24     4     1    35     -     -   166
    alaw     -    18     1     -    24     4     1    35     -     -   166
    g726     -    36    20    20     -    22    19    53     -     -   184
   adpcm     -    19     3     3    25     -     2    36     -     -   167
    slin     -    17     1     1    23     3     -    34     -     -   165
   lpc10     -    42    26    26    48    28    25     -     -     -   190
    g729     -     -     -     -     -     -     -     -     -     -     -
   speex     -     -     -     -     -     -     -     -     -     -     -
    ilbc     -    49    33    33    55    35    32    66     -     -     -

This board runs very well with a TDM400P card in it.

On another Via processor, this time a C3 running at 1GHz with 128KB cache:

          g723   gsm  ulaw  alaw  g726 adpcm  slin lpc10  g729 speex  ilbc
    g723     -     -     -     -     -     -     -     -     -     -     -
     gsm     -     -     4     4    12     4     3    20     -     -    72
    ulaw     -     6     -     1    10     2     1    18     -     -    70
    alaw     -     6     1     -    10     2     1    18     -     -    70
    g726     -    13     9     9     -     9     8    25     -     -    77
   adpcm     -     6     2     2    10     -     1    18     -     -    70
    slin     -     5     1     1     9     1     -    17     -     -    69
   lpc10     -    17    13    13    21    13    12     -     -     -    81
    g729     -     -     -     -     -     -     -     -     -     -     -
   speex     -     -     -     -     -     -     -     -     -     -     -
    ilbc     -    17    13    13    21    13    12    29     -     -     -

I'm finding these mini ATX boards with VIA processes to be generally very 
good for small-office applications. Low power, fanless, boot from flash, 
etc. and seem to just soak up everything thrown at them - until you need 
to do an excessive amount of transcoding, but thats virtually non-existent 
in my applications. (Although I'm using G726 on some IAX trunks over 
office ADSL lines here in the UK. (outgoing b/w typically 256Kbps on older 
installations, just over 400 on ADSL-MAX installations. In theory we can 
have up to (just over) 800Kbps on the business-class -MAX installations, 
but very few people are prepared to pay for it!!!

Gordon